This invention relates to a coupling tool for a double wall used to construct a double-walled building.
As shown in FIGS. 7 through 9, a double wall of a building has an inner wall 4 formed by laying ALC (aerated light-weight concrete) blocks 2 on base concrete 1 at an inner position and joining the seams between them by mortar 3, and an outer wall 7 formed by laying stones or bricks 5 at a position spaced a predetermined distance outwardly from the inner wall 4 and joining the seams by mortar 6, thereby defining a space 8 which is an air layer between the inner wall 4 and the outer wall 7. The space 8 provides heat insulation and dew formation preventive effect.
With this double wall, ALC blocks 2 forming the inner wall 4 are large and heavy, and thus show good stability during laying. In contrast, since stones or bricks 5 forming the outer wall 7 are small, the stability during laying is poor. Thus, it is necessary to couple and fix the outer wall 7 to the inner wall 4 to prevent the former from falling.
Heretofore, in a method for fixing the outer wall 7 to the inner wall 4, as shown in FIG. 9, coupling tools 9 formed by bending both ends of a metallic wire in the shape of L have been used. When ALC blocks 2 are laid, ends of coupling tools 9 are inserted in the seams between upper and lower ALC blocks 2 at suitable positions and buried in mortar 3 as shown in FIG. 7. When the outer wall 7 is constructed, the other ends of the coupling tools 9 are inserted in the seams between upper and lower stones or bricks 5 and buried in mortar 6. The coupling tools 9 serve to couple the inner wall 4 and the outer wall 7 together, thereby preventing the outer wall 7 from falling outwardly.
By the way, since the conventional coupling tools 9 extend between the seams between upper and lower ALC blocks 2 and the seams between upper and lower stones or bricks 5, they can be used only at portions where their seams align with each other.
But, since ALC blocks 2 and stones or bricks 5 are different in size from each other, when they are laid, there are only a few portions where the height levels of the respective seams coincide. Thus there are only a few locations where the inner wall 4 and the outer wall 7 can be coupled together by coupling tools 9. It was thus impossible to ensure a sufficient strength of joint of the outer wall 7 to the inner wall 4.
An object of this invention is to provide a coupling tool for a double wall which makes it possible to join an inner wall and an outer wall together at any height position, whereby the inner and outer walls can be joined together without selecting places, thereby ensuring a sufficient joint strength.